Originally Posted by chrugel  Hi,
Probably also convert to a ballscrew drive system on the heavy axis sinte the drive system there today is friction based. A metal wheel running on a steel beam.
I also wanted a stepper based system mainly beacause of simplicity but the decisionmakers want a servobased system. I think they are scared by the nature of open loop systems. 
I think the cuttingsize is about 1 x3m if I'm not misstaken.
I really hope i can convince them to choose a complete conversion kit.
best regards
Chris |
Ballscrew will not be nearly as forgiving to the harsh environment as Rack & Pinion. In addition on the 3M run you probably will not be able to keep the whip or wobble out of a screw. That is unless you fix the screw solid & drive the ball nut along the screw. Still the really fine metallic dust will be almost impossible to keep from contaminating the sustem causing premature failure of the screws.
To each his own on stepper vs servo. ("I think they are scared by the nature of open loop systems.") To me holds little value. Wonder if they realise the desktop printers & even larger such devices like map plotters. They depend on to make picture perfect letters, invoices, etc. are almost all stepper based systems.
Where the amount of weight (gantry) being moved isn't huge, and there are no cutting forces (router, endmill, etc.) to counteract. The expense & complexity of wiring + additional parts (encoders) to go bad,or get dirty & give false information, in a servo system doesn't make sense.
I am using one of CandCNC's stepper systems W THC. It works great & is simple to get hooked up & running. I have no experience with other systems so I can't advise you how
WWW.CandCNC.com stacks up against others out there. I only know they are selling a good product & stand behind it if you have trouble.
Good luck in your adventure.
Neil